Welcome to APC 
A 20G long is a nice size tank to start off with as your first planted tank.
Some good low light beginner plants are Anubias, Crypts, Mosses, Java Fern, four leaf clover (foreground), Hornwort, Ludwigia repens, Rotala, water sprite, Wisteria, Vallisneria, & sagittaria.
For low light plants you will want at least 1.5wpg (30 watts) with bulb rating of 6500k/6700k rating.
C02 is always benificial even in low light setups. Keep the bubble count (BSP) down & there will be no problems with hurting your fish. You could make your own (DIY) or buy a small system like Redsea or Hagan.
You may also want to read over, "Beginners Basic Introduction".
A 20G long is a nice size tank to start off with as your first planted tank.
Some good low light beginner plants are Anubias, Crypts, Mosses, Java Fern, four leaf clover (foreground), Hornwort, Ludwigia repens, Rotala, water sprite, Wisteria, Vallisneria, & sagittaria.
For low light plants you will want at least 1.5wpg (30 watts) with bulb rating of 6500k/6700k rating.
C02 is always benificial even in low light setups. Keep the bubble count (BSP) down & there will be no problems with hurting your fish. You could make your own (DIY) or buy a small system like Redsea or Hagan.
You may also want to read over, "Beginners Basic Introduction".